1. Field of the Invention
The present invention relates to a device including an embedded magnetic component transformer, and in particular, to an embedded magnetic component transformer with an improved winding design that improves an electrical performance of the transformer.
2. Description of the Related Art
It is known, for example, in US 2011/0108317 A1, to provide low profile transformers and inductors in which the magnetic components are embedded in a cavity formed in a resin substrate, and the necessary input and output electrical connections for the transformer or inductor are formed on the substrate surface. A printed circuit board (PCB) for a power supply device can then be formed by adding layers of solder resist and copper plating to the top and/or bottom surfaces of the substrate. The necessary electronic components for the device may then be surface mounted on the PCB.
Compared to conventional transformers, an embedded design allows a significantly thinner and more compact device to be built. This is desirable because typically the space available for mounting the transformer device onto a PCB, for example, a motherboard of an electronics device, will be very limited. A transformer component with a smaller footprint will therefore enable more components to be mounted onto the PCB, or enable the overall size of the PCB and therefore the entire device to be reduced.
When reducing the size of the transformer device, the adjacent turns of a transformer winding are likely to be provided more closely together, and the gap between separate windings provided on the transformer core is also likely to be reduced. As the windings heat up during use, these reduced separation distances can lead to the generation of hot-spots within the device, which can affect the performance of surrounding electrical components. In particular, those electrical components which control the transformer may be adversely affected by the hot-spots, with the result that the performance of the embedded transformer device is compromised. The need to reduce the overall transformer size tends to bring these electrical components into closer proximity with the transformer coils. This makes the electrical components more vulnerable to the coil heating and further compounds the problem. In addition, changing the positions of the electrical components can lead to a reduction in electrical isolation between the input and output sides of the transformer, increasing the risk of electrical arcing.
The undesirable heating effect on the electrical components positioned on the transformer windings can be mitigated by providing heat sinks, or making the circuit board larger to allow more space to be provided between the transformer and the components. It is also possible to correct for the effect of the heating electrically, for example, by increasing the capacitance of the transformer device or including additional stages of electrical circuitry. However, all of these possible solutions require an increase in the size of the embedded transformer device, which is often impossible due to tight restrictions on space.
In addition, differences in electrical path length between the transformer coil and the electrical components controlling the transformer can further degrade the performance of an embedded transformer device, particularly when combined with the heating effect discussed above.
Thus, the inventors of the invention described and claimed in this application have discovered that it would be desirable to provide an embedded transformer device having an improved electrical performance without requiring an increase in size, and a method for manufacturing such a device.